I could actually like Boss' amps quite a bit if it wasn't for their compression.
Their cab section could be useful too, but once you load IRs, they always sound weak in comparison - which solely seems to be because of their output level being decreased. Pretty bad (let alone the IR loading process via MIDI is as awkward as it possibly gets). In addition, as pretty much each and every cab section elsewhere, it could really need at least a simple low/high cut EQ.
Seriously, the GTs could be fantastic units - just that the Boss development team seems to have lost each and every connection to the real world. In addition to the amp quality (or rather lack thereof), onboard editing is horrible, controller assignments are a complete 80s style mess and their software editors all suck so much it's tough to believe. Too bad as the hardware itself is just excellent.